1. Field of the Invention
The present invention relates to a vehicle, such as a passenger car or a truck, which incorporates a loudspeaker system of a radio or a stereo sound system. More particularly, the present invention pertains to a door for a vehicle which incorporates a loudspeaker.
2. Description of the Related Art
Most loudspeakers for use in vehicles have heretofore been provided in the rear panel of a vehicle. However, when the sound comes from the rear, it is not very audible for the occupant of the vehicle. It is also impossible to produce satisfactory presence with the stereo sound when the sound emanates from the rear of the listener.
In order to overcome the above problem, arrangements in which a loudspeaker is mounted in a side portion of a vehicle have recently been proposed. One of them is a device wherein a loudspeaker is incorporated in a pillar of a vehicle, such as that disclosed in the specification of Japanese Utility Model Laid-Open No. 57687/1982. However, formation of loudspeaker-mounting holes in a piller leads to a reduction in strength of the vehicle body. In addition, a vehicle which has a relatively small pillar width can only be equipped with a loudspeaker having an extremely small diameter.
Another conventional arrangement is disclosed in the specification of Japanese Utility Model Laid-Open No. 130720/1982, wherein a loudspeaker is incorporated in a door panel. With this arrangement, it is possible to equip a vehicle with a loudspeaker the diameter of which is sufficiently large to ensure satisfactory sound volume in the compartment.
The arrangement in which a loudspeaker is incorporated in a door panel, however, suffers from the following disadvantages. Namely, since the position for mounting a loudspeaker is not particularly fixed, if a loudspeaker is disposed at an inappropriate position, it may happen that an obstruction such as the body of an occupant or a seat may block the sound from the loudspeaker. In addition, incorporation of a loudspeaker in a door panel may interfere with the interior arrangement of the door, resulting in an increase in the overall width of the door, or causing other constituent portions of the door to be restricted such as to compromise the structural strength of the door.